crank web

A later development was to enlarge the main bearings sufficiently to be larger than the entire crank web.

Some are so obvious that copper hammer marks are present on the crank webs.

The crank webs had the word Mamod stamped into them like the old SE3 it replaced.

Each piston had two parallel connecting rods, working on separated crankpin journals between the same crank webs.

The eccentric is enlarged in diameter until it too is bigger than the overall diameter of the crank web.

The big end bearings were flanged over the sides of the crankshaft to locate the rods against the crank webs, which reduced engine noise.

Rotating mass - e.g. Crank web weight uniformity and flywheel eccentricity (or lack there of)

Crank webs partially hitting the oil in oil pan (accelerating the oil mass rapidly) could be a big source of vibration.

Other configurations fall in between, depending on the bigend thickness, crank web thickness, and the main bearing width (if they exist in between the throws).

The crankshaft is a precision forged unit running in seven three-layer bearings, with counterweights bolted onto the crank webs, much like any other diesel motor of its vintage.

As a large gear could neither be formed in-place, nor passed over the crank webs, it could be machined separately and placed between two half-crankshafts with Hirth joints.

By making the crank webs with an offset to them, it is possible to place the main bearings closer together, closely sandwiching the rod passing between them, where this is now a narrower gap than the bearing size.

As offsetting the crank pin for as much as 60 no longer provides overlap in the diameter of the crank pin, the actual pin is not really an offset 'split' pin, but normally is completely separate in two parts with a thin crank web connecting the two individual pins.